High assault rate linked to lead: scientist

Nyrstar's lead and zinc smelter at Port Pirie in South Australia, December 17 2008

ABC News

A scientist researching the link between crime and lead pollution says it is one reason behind Broken Hill's high but falling assault rate.

Professor Mark Taylor from the Macquarie University in Sydney has compared levels of lead in the air of four NSW cities to the level of crime 20 years later.

It follows an American study that had the same result.

Broken Hill was not one of the cities studied, but Professor Taylor says crime statistics showing the city has twice the number of assaults as the rest of the state are consistent with his research.

"We found almost exactly the same pattern as they discovered in the United States as other people have discovered in other studies elsewhere in the USA: that is higher exposures of lead are correlated after 20 years to higher crime rates," Prof Taylor said.

Prof Taylor says other factors like genetics, poverty and poor education have a stronger influence on an individual's likelihood to commit crime.

"Lead is not the only factor," Prof Taylor said.

"We're saying other studies appear to shows it's contributed to the impact of rising crime rates and then declining rates as lead has been removed from the environment, and we're saying we're seeing these same sort of patterns in NSW."

Prof Taylor says 44 tonnes of lead are still released into the air in Broken Hill each year (mainly from tailings), way down from the 5,500 tonnes in the 1890s when there were 28 lead smelters in the city.

He says Broken Hill's rate of lead air pollution ranks only behind Mount Isa in Queensland and Port Pirie in South Australia.

"Short of removing all the soil in all of these locations, which would be the best solution, and that soil would have to go somewhere else, these educational advices to make sure children wash their hands, they don't put toys in their mouths that have been in the garden, they're all good things," he said.

"What we've seen over time is that blood lead has fallen in Broken Hill - it's fallen quite significantly since studies began in 1993."